not connected to each other

How would the underlined part of this phrase be translated? Essays should avoid clusters of ideas that are each linked to the prompt but not connected to each other. I don't like how this sentence sounds: Los ensayos deben evitar grupos de ideas que son conectadas al tema a desarrollar pero que no son conectadas entre sí. I don't like how "entre sí" sounds. Should I say "pero no son conectadas la una a la otra"?